DECLINE OF THE COASTAL BIRDS
Some species suffering as trawlers take fish stocks
NOTHING COULD look or sound more vibrant then the raucous noise of seabirds wheeling about the cliffs at Bempton during the annual breeding season.
But looks can be deceptive and, under the surface, there has been a dramatic decline in some species including the kittiwake, a gentle-looking gull which flies out hundreds of miles out to the North Sea to feed on shoals of small silvery fish called sand eels.
In the past 10 years, the breeding success of the kittiwake has halved due – conservationists believe – to the vast quantity of sand eels being hoovered up by industrial Danish trawlers from the sandy slopes of the Dogger Bank, a 300-mile round trip away.
Dr Euan Dunn, from the RSPB, said: “The sand eel fishery is the biggest single fishery by weight in the North Sea – and it is only a Danish fishery.
“We are confident that the fishery is taking a disproportionate amount of sand eels from Dogger Bank to the disadvantage of the seabird population that depends on them.
“We know from electronic tracking that the birds go all the way from Filey to fish there.”
It comes as a new study by the University of Aberdeen found a 70 per cent decline in seabird populations over seven decades due to a combination of commercial fishing, pollution, climate change and habitat destruction.
Scientists looked at the periods between 1970-1989 and 1990-2010 to assess the degree of competition seabirds faced for the food they survive on – anchovy, sardines, mackerel, squid, krill and crustaceans.
The team then estimated the annual amount the 276 seabird species would eat based on population counts and models, and compared it to the annual catches by fishing boats.
The scientists found that
The fishery is taking a disproportionate amount of sand eels. Dr Euan Dunn, from the RSPB.
the total annual seabird consumption fell from 70 million to 57 million tonnes between 1970-1990 and 1990-2010, while annual fishery catches soared from 59 to 65 million tonnes over the same period.
Dr Aurore Ponchon, who co-led the study, said: “This enhanced competition, in addition to other factors such as pollution, predation by invasive species on chicks, the destruction and changes in their habitat by human activities and environmental changes caused by climate change, puts seabirds at risk, making them the most threatened bird group, with a 70 per cent decline over the past seven decades.”
In the North Sea, climate change is having a major impact with a one degree rise in water temperature.
“It doesn’t seem a heck of a lot, but for an environment which has been stable since the end of the Ice Age, it is a dramatic change,” said Dr Dunn.
“All the fish and plankton have co-evolved with environmental conditions in the North Sea for thousands of years and we suddenly have this injection of temperature. That has reduced the abundance of plankton which sand eels feed on and we are seeing big reductions in sandeel abundance in the North Sea.”
The sand eels are turned into fish meal and oil to make feed for the salmon farm industry.
Sadly for Bempton’s seabirds, the go-to fishing area for the Danes is Dogger Bank, a significant part of which lies in UK waters. But Brexit may provide a solution. “The RSPB would like to see much stronger curbs on the sand eel fishery in the North Sea – particularly the UK part,” said Dr Dunn, who is optimistic UK fishermen would support a ban. “Brexit could help us.”